Track-jack.



Patented lune 26, I900. F. RDBINSDN.

TRACK JACK (Applicntion filed June 1, 1899.)

3 Sheets-Sheet I.

(No llodel.)

MTNEEEES R M M cams Prrrzn F Patented June 26, I900.

' ROBINSON.

TRACK JACK.

(Application filed June 1, 1899.)

3 Shaata-Sheol 2.

(No Model.)

TH T U 6% m I c m WITNESSES MW (Q.

No. 652,550., Patented June 26. I900. F. ROBINSON.

TRACK JACK.

- (Application filed. June 1, 1899.) (Nu flode l.) 3 Sheets-Sheet 3.

w "5 QzM/Z M NITED STATES FRANK ROBINSON, OF BANGOR, MAINE.

' TRACK-JACK.

$PEGIFICATION forming part of Letters Patent No. 652,550, dated June 26,1900.

Application filed June 1,1899. Serial No. 718,941. (No model.)

Bangor, in the county of Penobscot and State of Maine, have invented anewand useful Improvement in Track-Jacks, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, forming a part of this specification, inexplaining its nature.

The invention relates to a track-jack having the constructionhereinafter described.

In the drawings, Figure l is a view in perspective of the jack. Fig. 2is a view in vertical central section thereof, showing in dotted outlinethe depressed position of the jack-1everanditslifting-dog. Fig. 3isadetail View, also in vertical section, representing the op-' erationof the jack-releasin g devices, to which reference is hereinafter made.Fig. 4 is a view in horizontal section upon the dotted line 4 4 of Fig.2.

The jack-stand A has a suitable metal base ct and a metal column a,which rises from it, is ribbed or reinforced at a" upon its sides and aat its front, and has the lateral projections a, which are separatedfrom each other and which form cheek-pieces for supporting the pivot bof the handle B, thepivot c of the tripping-lever O, and the ways e forthe sliding dog E. These sides also act as a housing for thelifting-dog, tripping-lever, and tripping-dog. The jack-stand also has asquare central cavity a extending from top to bottom, and a long slit orrecess a in its back side, which opens into the central cavity and inwhich the guiding-foot f of the jackpost F extends. The jack-post has ahead f of any desired form, and it has upon its front face the notches fextending very nearly its entire length, and these notches have inclinedupper surfaces and straight lower sur' faces, and they are engaged bythe upper end g of the lifting-dog G. This lifting-dog is pivoted by thepivot g between the forked ends I) b of the lifting or operating lever B(see Fig. 4) and being overbalanced at its upper end maintains a contactwith the teeth and is brought into contact with one of them whenever thelever is moved downward. Its pivot g is placed closely to thelever-pivotb,

and as the lever is long great lifting power is thus provided for.

The inner part of the lever B is of iron or steel and has at its outerend a socket b for receiving the end I) of a wooden or other extensionN. The inner end of the said inner part of the lever b is madeespecially deep overthe lever-pivot b and under the liftingdog pivot gto provide sufficient strength to resist strains to which these partsare subupon each side of the jack-post, and the side sections of the dogalso extend beyond the tooth and upon each side of the jack-post,

and thereby provide a large and steady bear ing for supporting the jack.The sliding dog makes engagement with the teeth of the jack by beingautomatically moved to a tooth-en gaging position by means of a spring aconstantly bearing against the end of the prolong'ation c of thetripping-dog, said spring being held in part in a hole 0 in thejack-post and by a stud 0 which projects from the lever. 1

From the above description it will appear that the jack is lifted by themovement of the lever B, the upward movement thereof lowering'thelifting-dog with respect to the teeth of the jack and the downwardmovement thereof causing said lifting-dog to engage a tooth and tocontinue said engagement while it is being lifted with the jack by thelever. The upward movement of the j ack throws the sliding dog E out ofengagement by the contact of the inclined surface of the tooth which maybear against it with the inclined surface of the tooth of the dog. Thedog, however, is immediately automatically returned to en gage anothertooth at the end of each upward impulse communicated to the jack by thelift-:

ing-dog,'and it serves to hold the jack and its load while thelifting-dog is being moved downward vertically to engage another toothIt will be seen that the jack has but one set of teeth, which arealternately engaged by the lifting-dog and the sliding dog.. It willalso be seen that the lifting-dog is caused to engage the jack near theupper end of the jackstand and that this gives the jack a large range ofvertical movement.

I have arranged near the top of the jackpost, opposite the side engagedby the liftingdog, an antifriction-roll H, largely held in a cavity andagainst which the said side of the jack bears as it is being lifted,thereby converting the sliding friction at that point to a rollingfriction.

To release the jack-post, I have provided the lever B and thelifting-dog G with means whereby the lifting-dog may be held or lockedfrom engaging the teeth and may also bemoved to such a position that theend of a depending arm g forminga partthereof, may upon the downwardmovement of the lever B be brought into contact with the end of thedepending arm a of the feed-dog lever and cause it to be moved inwardsnfficiently to draw outward the sliding dog E to a releasing position,thereby leaving the jack ontirely free to drop. I have represented asone means ofso locking the feeding-dog to the lever a link I, which ispivoted at t to a lug i of the handle B and which in its operativeposition lies on top of the handle, as repreresented in Fig. 2. In itsoperative position it is moved from the position represented in saidfigure to that represented in Fig. 3,where it is shown as thrown overand as engaging a holding-lug at the upper end of the liftingdog. Thisis done when the lever B is at or near its highest position, and itholds the lower end of the lifting-dog in such a position that upon thedownward movement of the lever B the lower end of the lifting-dog levercomes into contact with the lower end of the slide-dog lever (see Fig.3) and disengages the sliding dog from the jack. After the jack has beentripped the link is disengaged from the lifting-dog and returned to itsnormal position. This releases the liftingdog and the tripping-dog, andthe jack is then in condition to be again immediately operated. Anyequivalent for the device for looking the lifting-dog to itsactuating-lever may be used. I

It will be seen that the extensions or checkpieces entirely cover theworking parts of the jack, with the exception of the upper part of thelifting-dog, enough of which is exposed to permit its attachment to itsoperating-handle, as above specified.

Having thus fully described my invention, I claim and desire to secureby Letters Pair ent of the United States- 1. In a track-jack, ajack-stand having lateral extensions or cheek-pieces near its top,

in combination with a jack-post mounted in the stand, having teeth inone side adapted to be engaged by the j aek-post-liftin g andjackpostholding devices, a jack-post-operating lever pivoted to thejack-stand. between its extensions or cheek-pieces and having an endextending inwardly beyond its pivotal point, a jack-post lifting anddropping dog pivoted to said innerend of said operating-lever entirelyinside the pivotal point of said lever, having a lifting arm or sectionwhich extends upward and inward from said lever to make engagement byits upper end with the teeth of the jack-post near the upper end of thejack-stand and above the jack-stand-holding device, and a tripping-armintegral with the lifting-arm and extending downward from the end ofsaid jack-post-operating lever, and jack-post-holding devices comprisinga slidedog mounted upon the jack-stand, a spring for automaticallyclosing the same and a disengaging-lever pivoted to the said jack-standand having a downward-extending arm with which the tripping end of thedog pivoted to the jack-post-operating lever is adapted to be broughtinto contact, as and for the purposes set forth.

2. In a jack, a jack-stand having lateral extensions or cheek-piecesnear its top, in combination with a jack-post mounted in the stand,having teeth in one side adapted to be engaged by the jack-post-liftingand jackpost-holding devices, a jack-post-operating lever pivoted to thejack-stand between its extensions or cheek-pieces, a jack-post-liftingdog pivoted to the inner end of said operatinglever inside of thepivotal point of said lever, which dog extends upward and inward fromsaid lever and makes engagement with the teethof the jack-postnear theupper end of the jack-stand, a downward-tripping extension of said dog,a lug upon the dog, a dog-locking device attached to the lever andadapted to make locking engagement with the dog-lug to lock the leverwith its tripping extension in operative relation, a slidingjack-post-holding dog, a spring for moving it into engagement andholding it in egagement with the post, a lever connected therewith whichis adapted to be moved to disengage the jack-post-holding dog by thetripping extension of the liftingdog when said dog is locked by itsoperatinglever.

3. In a track-jack, a jack-stand having lateral extensions orcheek-pieces near its top, in combination with a jack-post mounted inthe stand, having teeth in one side adapted to be engaged by thejack-post-lifting and jack-' post-holding devices, a jack-post-operatinglever pivoted to the jack-stand between its extensions or cheek-pieces,jack-post-lifting devices operated by the said jack-post-operatinglever, a jack-post-holding device comprising a slide-dog and a springfor moving it into engagement and holding it in engagement with a toothof the jack-post, a lever connected with said slide and extendingdownwardly therefrom, and a tripping-dog pivoted to said 3'ack-post-operatin g lever to extend downward therefrom and adapted to bemoved thereon and locked thereto to bring and hold its end in operativeposition to actuate the said disengaging-lever upon the downwardmovement of the said jack-post-operating lever, and means for lockingsaid tripping-dog to said lever.

4. In a track-jack, a jack-stand having lateral extensions near its top,a jack-post located within said stand and having teeth on its innervertical edge, a jack-post-operating lever pivotally mounted in saidlateral extensions and carrying a lifting dog pivotally mounted on itsinner extremity, in combination with a jack-post-holding device mountedin said extension between the end of said operating lever and saidjack-post, said liftingdog extending upwardly and inwardly to clear saidholding device and engage said jackpost teeth, and having an extensionbelow its pivotal connection to engage with and withdraw said holdingdevice from contact with said post-teeth, as set forth.

5. In a track-jack, a jack-stand having lateral extensions orcheek-pieces near its top, in combination with a movable jack-post mounted in the stand, having teeth upon one side which are engaged by thejack-post lifting and holding devices, a jack-post-operating leverpivoted between the extensions or cheekpieces, a lifting-dog pivoted tothe said operating-lever, which dog extends upward and inward from saidlever, makes engagement with the teeth of the jack-post near the upperend of the jack-stand, a hook-lug upon said lifting-dog near its upperend, a down ward tripping extension of said lifting-dog, a hook or linkpivoted to the upper side of the jack-post-operating lever to lie alongthe top of the same when in operative position, and

to be closed over the hook-lug of the liftingjack-post and hold itremoved therefrom and to bring it into operative position with itsjack-post-releasing extension, a jack-postholding dog, a spring to moveit to holding position, a tripping-lever to move it in a reverse ordisengaging direction, which lever is adapted to be operated by thetripping extension of the lifting-dog to disengage the saidjack-post-holding dog from the jack-post upon the downward movement ofthe operatinglever.

6. In a jack, a jack-stand in combination with a movable jack-postmounted in the stand, having teeth upon one side which are engaged bythe jack-post lifting and holding devices, a jack-post-operating leverpivoted to the jack-stand, a jack-post-lifting dog piv oted to saidoperating=lever, which dog ex tends upward and inward from said leverand makes engagement with the teeth of the jack-post near the upper endof the jackstand, a jack-post-holding dog movable in wardlyautomatically, a holding-dog-disen gaging lever connected at one endwith the holding-dog, a locking device for locking the jack-post-liftingdog to the jack-post-operating lever, cheek-pieces or extensions of thejack-stand to which said operating-lever and said holding-dog-trippinglever are pivoted, which cheek-pieces serve to inclose the saidholding-dog,its tripping-1ever and the greater part of the lifting-dogwith the exception of that portion engaged by the device which looks itto the jack-post-operating lever, as and for the purposes set forth.

FRANK ROBINSON.

In presence of- M. S. CLIFFORD, WILLIs Y. PATCH.

